Audio responsive apparatus for creating lighting effects

ABSTRACT

An electronic lighting control system for creating various automatic lighting effects, which include automatic fading, sequencing, and sound to light conversion. The apparatus allows simple programming of the desired lighting effects and is designed in simple modular form for easy expansion.

United States Patent [1 1 [111 3,869,699 Haller et al. Mar. 4, 1975 AUDIO RESPONSIVE APPARATUS FOR [56] References Cited CREATING LIGHTING EFFECTS UNITED STATES PATENTS [76] Inventors: John Jacob Haller, Boonton, N.J.; 3,636,515 1/1972 Smith 340/148 R Lawrence Silverman, lvorytown, Conn, Primary E.\aminerHar0ld J. Pitt [211 Appl. No.: 360,639 An electronic lighting control system for creating various automatic lighting effects, which include auto- [52] U S Cl 340/148 340/366 B matic fading, sequencing, and sound to light conver- [5 I] Gosh 5/36 sion. The apparatus allows simple programming of the [S8] Fie'ld B 261 desired lighting effects and is designed in simple mod- 84/464: ular form for easy expansion.

9 Claims, 10 Drawing Figures EXTERNAL AUDIO EQUlPMENT MATRIX PROGRAMMlNG SWITCH l 1 1 i 6 7 l 5 25 2s 27 28 I INVERTER i I l i 13 I I4 15 k {a t fi F /7 1e 19 2o 1 VOLTAGE VOLTAGE VOLTAGE VOLTAGE I 54 CONTKOLLED commoner: OONIROLLED comizouso DlMMEl DIMME ll DIMMER DIMMER t l. l

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. A mEgg/m I 41975 sum ounr 10 PATENTEDHAR 197s SHEET OSUF 10 PATENTED 4195 SHEET O'IUF 10 Iut w OSLDOU a 02M g OU 10:26 QZOEUS PATENTEDMR 41975 3.869.699

SHEET UBUF 10 I 1 -Q Q Q, 9 \Q Q o O O Q X PATENTEB 41975 SHEET USUF 10 PATENTEDHAR SHEET lOUF 10 \N mUaDom AUDIO RESPONSIVE APPARATUS FOR CREATING LIGHTING EFFECTS BACKGROUND OF THE INVENTION This invention relates to a lighting control system and in particular for use in a multipurpose lighting system in which it is desired or required that the effects of the lighting in an area must be changed frequently. Variation in effects may range from an intense music controlled lighting environment to a very subtle change in background lighting. Such requirements can be found in many applications such as night clubs, restaurants, stage, and display lighting.

Lighting effects generators in the prior art were designed to produce only a single lighting effect. If a more complicated effect was desired, it was necessary to obtain a large number of generators. Since these generators were constructed only with a pair of output terminals for connection to the lamp load, in order to program such a combination of generators, it was necessary to use high power level switching equipment. In addition, if the generators were all centrally located, it usually required that a long power line had to be connected from the output of each generator to its corresponding lamp load. The flexibility of such a system was usually limited, since the power control section of the lighting effects generators was committed to performing only the single specified function of that generator.

SUMMARY OF THE INVENTION It is the object of the invention to provide an apparatus for creating lighting effects in which a complicated lighting effect may be easily programmed, by the use of low power level switching equipment.

It is also an object of the invention to provide a system comprising separate control and function generating modules for maximum flexibility in that the power control section of the system can be connected to any function generator in the system. The splitting of the system in modular parts also allows savings in cost and versital construction, since the systems complexity can be simply varied by the number of modules utilized.

It is further an object of the invention, comprising the said function generating and power control modules, to allow the remote location of said power control modules at a point close to the desired lamp load, while still allowing the function generating section to be centrally located. This method eliminates the necessity of lengthy runs of power lines to the lamp loads.

In accordance with the invention an apparatus for creating lighting effects comprises a means for generating a first plurality of electrical signals, a second plurality of lamp intensity control means and means for selectively switching the first plurality of electrical signals to the second plurality of intensity control means. In further accordance with the invention, the generating means comprises, means for supplying audio signals, first means responsive to the audio signals and having at least three output terminals, for generating a d-c output signal and at a predetermined rate, the rate being controlled by the amplitude of the audio signals, and means for generating at least one electrical signal having a triangular waveform.

LII

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the elements of the lighting control system;

FIG. 2 is a block diagram of the audio to dc voltage converters;

FIG. 3 is a block diagram of a preferred embodiment of the sequencer;

FIG. 4 shows in graphic form electrical waveform useful to explain the operation of the apparatus shown in FIG. 3;

FIG. 5 is a schematic representation of the preferred embodiment of the auto-fade circuit;

FIG. 6 shows in graphic form electrical waveforms useful to explain the operation of the apparatus shown in FIG. 5;

FIG. 7 is a block diagram of the dimmer;

FIG. 8 shows in graphic form electrical waveforms useful to explain the operation of the apparatus shown in FIG. 7;

FIG. 9 is a schematic representation of a preferred embodiment of the dimmer; and

FIG. 10 is a schematic representation of a preferred embodiment of the sequencer.

DESCRIPTION OF PREFERRED EMBODIMENTS The preferred embodiment of the invention as shown in FIG. 1 comprises a means for generating a first plurality of electrical signals, hereinafter called the function generator section 22, a second plurality of intensity control means comprising voltage controlled dimmers 24, and a means for selectively switching the plurality of electrical signals to the plurality of intensity control means, hereinafter referred to as the programming and signal modification section 23. The first plurality of electrical signals generated by the function generator section 22 are hereinafter called control signals. The voltage controlled dimmers 24 vary the intensity ofthe lamp loads 32-35 in response to the said con. trol signals. These d-c signals vary from zero volts, representing zero illumination, to a predetermined voltage level representing full illumination. Any control signal can be coupled to any dimmer, or a plurality of dimmers, by use of the programming and modification section 23. Also through the use of the programming and modification section 23, a background level signal may be mixed with the control signal, or the control signal may be inverted, to provide a complementary effect. An audio source 21, which is a means for supplying audio signals to the function generating section 22, comprises external equipment in the form of a tape recorder, record player or other source of audio inform ation to produce audio signals at either speaker or line level.

The function generating section 22 shown in FIG. 1 is comprised of three component blocks 1, 2 and 3. The first component block called the sequencer comprises a first means responsive to the audio signals supplied from the audio source 21. The sequencer has at least three output terminals which are represented as the output lines 29 of block 1. A d-c output signal appears at each output terminal in a predetermined sequence and at a rate determined either by the amplitude of the supplied audio signal or by a setting ofa manual control (not illustrated). A description of the sequencer as embodied in FIGS. 3, 4 and 10 is set forth below.

The second component block of the function generating section 22 is the audio to d-c voltage converter 2, which comprises a second means responsive to the audio signals supplied from the audio source 21. The audio signals are here converted into d-c signals which appear at the output lines 30 of block 2. A more detailed description of the audio to d-c voltage converter is set forth below with reference to FIG. 2.

The third component block of the function generating section 22 is the auto-fader 3, which comprises a means for generating an electrical signal having a triangular'waveform at output 31 of block 3. A more detailed description of this component is set forth below with reference to FIGS. and 6.

The matrix programming switch 4 allows switching of any function generator output line 29, 30'or 31 to any or all of the dimmer input lines 5-8. A preferred version of this switch is the matrix switch manufactured by the Cherry Electric Corp. The control signals once programmed to the desired dimmer line may still be modified by the inverter me'ans 25-28 and background level controls 13-16. The inverter 25 for example inverts the electrical signal on dimmer line 5. The output of inverter 25 is coupled to invert switch 9 connected to the input of dimmer 17. Through the use of switch 9, the input terminal of dimmer 17 is coupled to either the normal signal on dimmer line 5 or the inverted signal at the output of inverter 25. The background level control 13 mixes an adjustable d-c level with the electrical signal at the input of the dimmer 17.

FIG. 2 is the block diagram of the preferred embodiment of the audio amplitude to do voltage converter 2. The device is driven by a source of audio 21 which enters the automatic gain control circuit 36. This circuit comprises a variable gain amplifier and an averaging circuit at its output. The averaging circuit controls the gain of this amplifier in such a way as to keep the amplitude variations at its output relatively constant for large variation in input signal amplitude. The output of the automatic gain control is then split into three band pass filter amplifiers 37-39 which can be tuned for various frequencies in the audio range. The outputs of the filters are then passed through halfway rectifier d-c amplifier sections 40-42 where the audio is rectified and the resulting voltage amplified to give the desired d-c voltage. Output level controls 43-45, comprising potentiometers, control the maximum voltage of the d-c signals at output terminals 46, 47, and 48.

FIG. 3 is a block diagram of the preferred embodiment of the previously mentioned sequencer 1. The device comprises a means for generating a first signal having a sawtooth waveform (as shown in FIG. 4a) hereinafter referred to as sawtooth generator 52. The sawtooth generator 52, is comprised of an integrator 54 and a reset circuit 53. The output of integrator 54 generates a linear descending ramp voltage, starting at a predetermined voltage level V as shown in FIG. 4a. The reset circuit 53 senses the point when the ramp voltage at the output of integrator 54 reaches a predetermined voltage level V and resets the output of integrator to V... thus producing the sawtooth waveform shown in FIG. 4a.

The period of the said sawtooth waveform may be controlled by either of two means. The first is responsive to the variations of amplitude of said audio signals from audio source 21, and is hereinafter called the audio rate control 49. The second means comprises a variable resistance means and is hereinafter called a manual rate control 50. Either manual control 50 or audio control 49 may be selected by use of switch 51, which is connected to the input of the integrator 54.

A means for supplying second and third signals having fixed voltage levels of V, and V, respectively, is incorporated in the voltage level source 65. A first comparator means, shown as comparator 56, is responsive to the sawtooth waveform at the output of integrator 54 and voltage level V,, from the voltage level source 65. The output of comparator 56 has a first d-c voltage level of magnitude V when the instantaneous amplitude of the sawtooth waveform exceeds the voltage level V,,, as shown in FIG. 40.

A second comparator means, shown as comparator 57, is responsive to the sawtooth waveform and the voltage level V,. Comparator 57 generates a predetermined d-c voltage, of magnitude V at its output when the magnitude of voltage level V, exceeds the instantaneous amplitude of the sawtooth waveform, as shown in FIG. 4e.

A means, responsive to the output signals of comparator 56 and comparator 57, can be a nor gate 55. The inputs 58 and 60 of nor gate 55 are coupled to the outputs of comparator 56 and comparator 57, respectively. The output of the nor gate 55 responds to the outputs of said comparators in such a way as to produce a first voltage level with a magnitude of 0.3 volts, when there is a d-c voltage level at either of said comparator outputs. If said d-c voltage level is absent from the outputs of said comparators, the output of nor gate 55 assumes second volta'gelevel of magnitude V,,, as shown in FIG. 4d.

A pulse of amplitude V and period equal to one third of the period of the sawtooth waveform will appear sequentially, first at the output of comparator 56, then at the output of nor gate 55 and finally at the output of comparator 57. The preceding outputs are connected to output level control 1, 61 output level control 2, 62 and output level control 3, 63. Through the use of said output level controls the amplitude of said pulses, on

output lines 64-66, can be varied, by potentiometer means, from a magnitude of zero to a magnitude of V,,.

To eliminate an unwanted pulse at output 2 during the reset period of the sawtooth generator 53, the reset voltage waveform FIG. 4b at the output of the reset circuit 53 is applied to the third input 59 of nor gate 56 to blank out the channel during reset.

FIG. 5 shows a schematic diagram of the preferred embodiment of the previously mentioned auto-fade circuit. This circuit is used to form the triangular waveform shown in FIG. 6a. Operational amplifier 67 in conjunction with capacitor and resistor 69 form an integrator circuit, whose operation is defined in the well-known principles involving operational amplifiers. Resistor 68 limits the current in operational amplifier 67 in case of accidental discharge of capacitor 70 and diode 71 prevents capacitor 70 from going negative.

Consider the voltage at point 73 on potentiometer 72- to be negative and nearly V-. This causes integrator amplifier 66 to generate a positive linear ramp voltage. The slope of the ramp is controlled by varying the voltage to resistor 69 by means of potentiometer 72. The

and trim potentiometer 79. When the ramp voltage at the non-inverting input 75 exceeds the ramp voltage at the inverting input 76, the amplifier 77 switches positive. This causes point 73 on potentiometer 72 to become positive and causes the integrator amplifier 67 to start a linear ramp with a negative slop. At the same time that the output of amplifier 77 switches positive, it also turns on transistor 79 through resistor 82. Collector 84 of transistor 80 is connected to the inverting input 76 of ampliifer 77, and since transistor 80 is driven into saturation, input 76 is now at 0.2 volts positive. The decreasing ramp voltage of non-inverting input 75 continues until it reaches 0.2 volts and then the cycle repeats itself. The resultant waveform at the output 86 of potentiometer 85 is shown in FIG. 6a and is a triangular waveform. The output of amplifier 77 is a bi-directional square wave shown in FIG. 6b and the voltage at collector 83 of transistor 79 is shown in FIG. 60.

Since the speed control potentiometer 72 has a logarithmic taper it provides a wide frequency range. Potentiometer 85 sets the maximum output level of the triangular waveform. Diode 81 prevents breakdown of the base emitter junction at transistor 80 when the output of amplifier 77 is negative. Capacitor 82 lends stability toamplifier 77.

FIG. 7 illustrates a block diagram of the preferred embodiment of a lamp intensity control (hereinafter called a dimmer) having a pair of output terminals for connection to a lamp. The dimmer comprises a pair of output terminals 99 and 100 to which are supplied a time varying a-c waveform of phase control form shown in FIG. 4/2. The angle of conduction of the said waveform is controlled by a positive d-c signal, shown in FIG. 8a, applied to the input 87.0f the dimmer. An increase in said d-c signal yields an increase in said conduction angle. The signal applied to the input 87 is modified in such a way as to produce at the output 90 of comparator 89, the periodic signal having positive and negative voltage levels as shown in FIG. 8e. The duration of the positive voltage level of the signal in FIG. Se is equal to the duration of conduction of the controlled rectifiers 98 which control the phase control waveform, FIG. 812, at said output terminals 99 and 100.

As shown, the dimmer contains a negative feedback loop comprising integrator summer 88, comparator 89, and electronic switch 91. The feedback loop is used to produce the desired response between the light output ofa lamp 101 connected to the output terminals 99 and 100, and the dc signal applied to the dimmer input 87.

The integrator summer 88 comprises an integrating summation means for generating a first signal shown in FIG. 8b. The said first signal is an average of the algebraic sum of the positive d-c signal at input 87, and a negative third signal from the electronic switch 91 which latter signal has a waveform as shown in FIG. 83.

The first signal is applied to one input of comparator 89. The sawtooth waveform generator 95, comprising a means for generating a second signal having a sawtooth waveform, is connected to the other input of comparator 89. Comparator 89 comprises a comparator means responsive to said first and second signals and generates a signal, at output 90, having the waveform shown in FIG. 8e. The signal (FIG. 8e) has a first voltage level equal to a negative voltage V when the magnitude of the first signal, shown in FIG. 8b exceeds the magnitude of the second signal (FIG. 8d), and has a second voltage level equal to a positive voltage V when the magnitude of the second signal exceeds the magnitude of the first.

Power supply 92 serves as a means for generating a negative fullwave rectified sine wave, shown in FIG. 8f, at output 93. The said output 93 is coupled to electronic switch 91. The electronic switch 91, comprises the means for generating the third signal supplied to summing integrator 88, and is gated by the output of comparator 89. The negative fullwave rectified sine wave, which is applied to the input of the electronic switch, is then gated by that switch to create the wave form of the third signal, shown in FIG. 8g. The duration of the conduction angle of the wave form is controlled by the duration of the positive voltage V2 at the output 90 of comparator 89. It is apparent that increasing the d-c signal at the input 87 of the dimmer produces a larger conduction angle of the third signal, but since the third signal is negative with respect to the d-c signal at the input, the algebraic summation of the two signals will effectively reduce the magnitude of the input signal; thus the third signal can be considered as producing a negative feedback effect.

As previously mentioned, the outupt signal of comparator 89 in FIG. 8e, controls the conduction angle of controlled rectifiers 98. This effect is accomplished by optical coupling switch 96 and firing circuit 98. The optical coupling switch 96 forms a means for coupling the output 90 of comparator 89 to the input of firing circuit 97. The optical coupling is used to isolate the control circuitry from the a-c line to prevent a.shock hazard and to prevent transients on the power lines from destroying the previously mentioned control circuitry. The firing circuit 97 is used to provide a means for generating and coupling a firing signal to said control rectifiers 98. The control rectifier 98 as mentioned before, forms a means for controlling the waveform of the time varying voltage supplied to the output terminals 99 and 100.

The sawtooth waveform generator 95, as mentioned previously, produces the sawtooth waveform shown in FIG. 8d. The period of said sawtooth waveform is equal to one half the period of the a-c line. The sawtooth waveform generator is coupled to output 94 of power supply 92. The waveform of output 94 is a positive fullwave rectified sine wave shown in FIG. 80, which is used by the sawtooth waveform generator to reset the sawtooth generator at each zero crossing of the waveform FIG. 80.

FIG. 9 shows a schematic diagram of the preferred embodiment of a particular variation of the dimmer shown in block diagram 7.

The previously mentioned integrator summer 88 comprises an operational amplifier 106 in conjunction with capacitors and resistors 102, 103 and 138 forming standard summing integrator circuit. The explanation of said summing integrator is found in standard texts on operational amplifier theory or analogue computors. Resistors 102 and 103 are connected between the input terminal 87 and the inverting input 104 of amplifier 106, and resistor 138 is connected from point 134 in the electronic switch 91 to the input 104. Input 104 serves as a summing node for the current in resistors 102 and 103, from the positive d-c input signal and the current in resistor 138 caused by the previously mentioned negative third signal from the electronic switch 91. Capacitor 110 averages said summed currents causing an output voltage at output 107 of amplifier 106. Diode 111 shunts capacitor 110 to prevent the output 107 from going negative.

Comparator 89 comprises an operational amplifier 116, operated in the open loop mode and having differential inputs 114 and 115. The inverting input 114 is connected to output 107 of amplifier 106 through a low pass filter, resistor 112 and capacitor 113 which provides further smoothing of the first signal from the integrator summer 88.

The noninverting input 115 is connected to the sawtooth waveform generator 95 through resistor 119. Since the gain of amplifier 116 is large, approximately 80 decibles, if voltage at the inverting input 114 exceeds the voltage at the noninverting input 115 by a few millivolts the output 90 will be saturated at negative voltage V,. If the voltage level at input 115 exceeds that at 114 the amplifier output 90 is driven positive to voltage V Electronic switch 91 is comprised of transistor 137, diode 133, and resistors 139 and 132. The base 136 of transistor 137 is'connected to the output 90 of comparator 89 through resistor 132. Resistor 139 is connected from negative full wave rectified voltage, at point 93 of power supply 92, to junction 134 of the collector of transistor 137 and resistor 138 of the summing integrator 88. When output 90 of comparator 89 is at voltage level V transistor 137 is turned on causing the current in resistor 139 to be shunted to ground. If the output I of 90 is at voltage level V transistor 137 is cut off and the current in 139 flows into the summing integrator 88. Diode 133 serves to prevent the voltage between base 136 and emitter 135 from exceeding the break down limit when transistor 137 is cut off. ln'this manner, the previously referred to third signal, shown in FIG. 8g, is generated.

An optical coupled switch means 96 is comprised of transistor 155, controlling light emitting diode 156, which in turn triggers photosensitive SCR 160. When output 90 is at voltage level V the transistor 155 shuntsthe current from resistor 151 away from light emitting diode 156. When output 90 is at voltage level V transistor 155 is cutoff causing the current in resistor 151 to flow through light emitting diode 156 turning it on. The photo-sensitive SCR 160 is then turned on by the light emitting diode 156.

The firing circuit 97, comprising diode bridge 167 and resistor 168, is used in conjunction with photosensitive SCR 160 to fire the controlled rectifiers 98, which in this case comprises triac 172. Triac 172 is connected in series with lamp 110 which is connected to output terminals 100 and 99 of the dimmer. The said series connection is across a source of 21-0 voltage designated in the drawing as L and N. It is desired to turn on triac 172 at the proper time during the half cycle of an a.c. line voltage, by applying a firing signal to gate 1 terminal 170 of triac 172. It is preferred that the polarseries with terminal 171 of triac 172 prevents damage to said triac in case of a short circuit across terminals 99 and 100. 7

It is apparent to one skilled in the art that with the addition of another photo coupled switch and the deletion of diode bridge 167, triac 172 could'be replaced by a pair of inverse parallel SCRs.

The sawtooth waveform generator comprises resistor 124, charging capacitor 125, and a noninverting switch means for periodically discharging capacitor 125, where said noninverting switch means comprises transistors 129 and 123 and resistors 131, 130. Resistor 131 is connected from point 94 of power supply 92, which is a source of'positive full wave rectified voltage, to the base 128 of transistor 129. The collector of transistor 129 is connected to the base 122 of transistor 123, which is also connected to resistor 130 from the positive supply voltage. When the voltage at point 94 exceeds 0.6 volts, transistor 129 turns on,shunting the current flowing in resistor from the base 122 of transistor 123 which has its collector connected to capacitor 125. When the voltage at point 94 drops below 0.6 volts, transistor 129 cuts off, and the current from resistor 130 turns on transistor 123, which discharges capacitor 125.

The power supply 92 comprises a switch 176 which connects the primary of transformer 177 to the ac line. The secondary of this center-tapped, step-down transformer 177 is connected to the ac. inputs 140, 141 at the diode bridge 142; the center tap goes to ground and negative voltage at points 145 and 148 respectively. All points on the diagram marked V+ are connected to point 145, and all points marked V are connected to 148. Terminals 108 and 109 of operational amplifier 106 and terminals 117 and 118 on amplifier 116 are power connections for the amplifier and are marked with proper V+ and V- markings.

A typical embodiment of the circuit shown in FIG. 9, which was constructed and successfully operated, had the following parts values:

Resistor 102 50K ohm trim potentiometer Resistor 103 4 68K ohm Resistor 138 33K ohm Resistor 132 470K ohm Resistor 139 57K ohm Resistor 112 22K ohm Resistor 119 22K ohm Resistor 124 68K ohm Resistor 130 22K ohm Resistor 131 K ohm Resistor 149 10K ohm Resistor 151 820 ohm Resistor 162 27K ohm Resistor 168 100 ohm Resistor 173 100 ohm Capacitor 0.22 mfd Disc 50V Capacitor 113 0.05 mfd Disc 50V Capacitor 0.08 mfd Disc 50V Capacitor 147 125 mfd electrolytic 15V Capacitor 144 250 mfd electrolytic 15V Capacitor 174 0.1 mfd tubular 200V Transistor 137 2N5138 Transistor 155 2N5l38 Transistor 123 2N3393 Transistor 129 2N3393 Diode 146 1N914 Diode 143 1N9l4 Diode l33'- 1N9l4 Diode 111 1N9l4 Diode 150 1N9l4 Operational Amp 106 LM 741C National Semiconductor Operational Amp 116 LM 741C National Semiconductor Optical lsolator 191 MCS-2Monsanto Diode Bridge 167 lamp 200 PIV Diode Bridge 142 lamp O PIV Triac 172 Q2040 PFC Electronic Controls Corporation Transformer 177 8V-O-8V 0.5 amp secondary 1 17V primary FIG. is a schematic diagram of the preferred embodiment of the sequencer, shown in block diagram form in FIG. 3. The amplifiers (179, 186, 199, 205) are current differencing-type operational amplifiers, preferably type LM 390 ON made by National Semiconductor Corp. These monolithic integrated amplifiers come four to a package and are very inexpensive. Amplifier 179 in conjunction with resistor 183 and capacitor 182 form an integrator network. current flowing from switch 51 into inverting input 180 causes a linear descending ramp voltage to be generated at the output of amplifier 179. This circuit forms the integrator 54.

The output 184 of amplifier 179 is fed through resistor 190 to the inverting input 187 of amplifier 186, which forms the reset circuit 53. Resistor 191 provides bias current into the noninverting input 188 of amplifier 186. With the voltage at output 184 of amplifier 179 equal to V current flowing into input 190 has a magnitude that is greater than the bias current flowing into input 191. This causes the output 189 of amplifier 186 to be held to approximately zero volts. As the ramp voltage at the output 184 of amplifier 179 decreases, it reaches voltage level V,,; at this point the current into the input 191 is less than the bias current into input 191, causing the output 189 to be driven to voltage level V,. The output 189, being connected through resistor 185 to the noninverting input 181 of amplifier 179, causes a large current to flow into noninverting input 181 when output 189 is at voltage level V,-. The large current into noninverting input 181 is much greater than the current into inverting input 180, so that the current into noninverting input 181 predominates over the current into inverting input 180, when the said two currents are differenced inside the amplifier. This results in a very rapid increasing ramp voltage, resetting the output 184 of amplifier 179 to voltage level V,,. When the output 189 of amplifier 186 is at voltage level V it produces a current through resistor 192 into noninverting input 188, which is much greater than the bias current from resistor 191. When the increasing ramp voltage at the output 184 of amplifier 179 reaches V,,, the current into input 187 of amplifier 186 is greater than the current into input 188 from resistor 192, causing the output 189 to be driven to zero. This removes the current at the non-inverting input 181 of amplifier 179, causing the amplifier to generate a decreasing ramp voltage again, thereby generating the desired sawtooth waveform.

The manual rate control comprises a potentiometer 194 connected in series with resistor 195; said series connection is placed between V+ and ground. The wiper of potentiometer 194 is connected to resistor 193, which is connected to switch 51. With switch 51 in the manual position, current flows through resistors 193 and 183 into input 180. The magnitude of said cur rent, and consequently the period of the sawtooth waveform, are controlled by setting the potentiometer. Resistor 195 sets the level for the maximum period desired.

The audio rate control 49 comprises step up audio transformer 198 with its primary connected to audio source 21 and its secondary connected to a diode 197 and filter capacitor 191, which is a halfwave rectifier circuit. The voltage across filter capacitor 196 varies with the amplitude of audio source 21, and is coupled through switch 51 and resistor 183 to input 180 in order to vary the period of the sawtooth waveform.

Voltage level source 65 comprises resistors 211, 212 and 213 connected in series between V-land ground. The voltage level V is derived from the junction of resistors 211 and 212, and the voltage level V, from the junction of resistors 212 and 213.

The comparator 56 is comprised of amplifier 199 and resistors 204 and 203. The noninverting input 201 of amplifier 199 is connected through resistor 204 to the output 184 of amplifier 179, which provides the sawtooth waveform; the inverting input of amplifier 199 is connected through resistor 203 to voltage level V,,. When the sawtooth waveform is greater than V the current in the noninverting input 201 is greater than the current in the inverting input 200, causing the out put 202 of amplifier 199 to be at voltage level V When the sawtooth waveform voltage drops below voltage level V,,, the current in the noninverting input 201 is less than the current in the inverting input 200, causing the output 202 to go to zero.

Comparator 57, comprising amplifier 203 and resistors 210 and 209, is similar to said comparator 56 but with the exception that the said sawtooth voltage is connected to the inverting input 206, and the noninverting input is connected to voltage level V The difference in response of the output 208, as compared to output 202, is that output 208 is at V when the value of the sawtooth waveform is less than the voltage level V and at zero when the value of the sawtooth is greater than V1,.

Nor gate is comprised of transistors 217 and 219 and resistors 214, 215, 216, and 218. One side of each of resistors 214, 215 and 216 is connected in common to the base of transistor 217. Gate inputs 58, 59 and are the remaining sides of resistors 214, 215 and 216 respectively. lfa voltage level appears at any one of the inputs 58, 59 or 60, transistor 217 is turned on, and the voltage level at collector 220 is 0.3 volts. If there is no voltage present at any input, the voltage at collector 220 is V Transistor 219 is connected as an emitter follower, so that a load at output 221 does not load down the voltage at collector 220.

Output level controls 61, 62 and 63 are comprised of potentiometers 222, 223 and 224 respectively for varying the maximum output voltage on output lines 64, and 66.

What is claimed is:

1. ing:

An apparatus for creating lighting effects comprisa. means for generating a first plurality of low power b. means for electrically coupling said low power d. a second plurality of lamp intensity control means,

each having input terminal means, responsive solely to said low power electrical signals intercoupled to said output terminals; and

e. means for electrically coupling said output terminals to said input terminal means of said plurality of lamp intensity control means.

2. An apparatus according to claim 1 in which said generating means further includes second means also responsive to said supplied audio signals for converting said signals into at least one d-c low power electrical signal, having an amplitude proportional to the amplitude of said supplied audio signals.

3. Apparatus according to claim 2, wherein each of said second plurality of lamp intensity control means has a pair of output terminals for connection to a lamp, and comprises:

a. integrating summation means for generating a first signal;

b. means for generating a second signal having a sawtooth waveform;

0. means for supplying a d-c signal to said integrating means;

d. electronic switch means for supplying a third signal to said integrating means, said electronic switch means being gated by the output signal of the nextmentioned comparator means, to produce said third signal;

. comparator means responsive to said first and second signals for generating an output signal, said output signal having a first voltage level when the magnitude ofthe first input signal exceeds the magnitude of the second, and having a second voltage level when the magnitude of the second input signal exceeds the magnitude of the first;

I means for coupling the output of said comparator means to said electronic switch means;

g. means for generating anegative fullwave rectified sine wave; and coupling said sine wave generating means to the input of said electronic switch means;

h. means for supplying time-varying voltage to said pair of output terminals;

i. means for controlling the waveform of said timevarying voltage comprising controlled rectifier means;

j. means for generating and coupling a firing signal to said controlled rectifier means; and v k. means for coupling the output of said comparator means to the input of said firing signal generating means, comprising an optical coupled switch means. 4. Apparatus according to claim 2' wherein first means responsive to said audio signals comprises:

a. means for generating a first signal having a sawtooth waveform;

b. means for supplying a second signal having a fixed voltage;

c. means for supplying a third signal having a fixed voltage; g d. first comparator means responsive to said first and second signalsfor generating a first output signal, having a first d-c voltage level when the instantaneous amplitude of the first signal exceeds the magnitude of the said second signal;

e. second comparator means responsive to said first and third signals for generating a second output signal, having a predetermined d-c voltage level when the magnitude of the third signal exceeds the instantaneous amplitude of the first signal;

. means responsive to the output signals of said first and second comparator means, said means including an outupt port and potentiometer means for varying the signal level at said output port for generating a third output signal having a first voltage level when there exists a d-c voltage level at either output of said first and second comparators, and for generating an output signal having a second voltage level, when a d-c voltage is absent from both outputs of said first and second comparator means; I

g. means for controlling the period of said first signal 4 means responsive to said audio signals comprises:

a. means for generating a first signal having a sawtooth waveform;

b. a means for supplying a second signal having a fixed voltage;

c. a means for supplying a third signal having a fixed voltage;

d. first comparator means responsive to said first and second signals for generating a first output signal, having a first d-c voltage level when the instantaneous amplitude of the first signal exceeds the magnitude of the said second signal;

e. second comparator means responsive to said first and third signals for generating a second output signal, having a predetermined d-c voltage level when the magnitude of the third signal exceeds the instantaneous amplitude of the first signal;

f. means responsive to theoutput signals of said first and second comparator means, said means including an output port and potentiometer means for varying the signal level at said output port for generating a third output signal having a first voltage level when there exists a d-c voltage level at either output of said first and second comparators, and for generating an outupt signal having a second voltage level, when a d-c voltage is absent from both outputs of said first and second comparator means;

g. variable resistance means for controlling the period of said first signal having a sawtooth waveform, in response to the amplitude of the said audio signals; and

h. potentiometer means for varying the maximum level of the output signals of said first and second comparator means.

6. An apparatus for creating lighting effects comprising:

a. means for generating a first plurality of electrical signals;

b. a second plurality of lamp intensity control means wherein each of said second plurality of control means has a pair of output terminals for connection to a lamp, and comprises:

i. integrating summation means for generating a first signal;

ii. means for generating a second signal having a sawtooth waveform;

iii. means for supplying a d-c signal to said integrating means;

iv. electronic switch means for supplying a third signal to said integrating means, said electronic switch means being gated by the output signal of the next-mentioned comparator means, to produce said third signal; comparator means responsive to said first and second signals for generating an output signal, said output signal having a first voltage level when the magnitude of the first input signal exceeds the magnitude of the second, and having a second voltage level when the magnitude of the second input signal exceeds the magnitude of the first;

vi. means for coupling the output of said comparator means to said electronic switch means;

vii. means for generating a negative fullwave rectified sine wave; and coupling said sine wave generating means to the input of said electronic switch means;

viii. means for supplying time-varying voltage to said pair of output terminals;

ix. means for controlling the waveform of said time-varying voltage comprising controlled rectifier means;

x. means for generating and coupling a firing signal to said controlled rectifier means; and

xi. means for coupling the output of said comparator means to the input of said firing signal generating means, comprising an optical coupled switch means; and

0. means for selectively switching said plurality of electrical signals to said plurality of intensity control means.

7. An apparatus according to claim 4 wherein the means for controlling the period of said first signal comprises a variable resistance means.

8. An apparatus according to claim 2, further including means, electrically connected between said output terminals of said programable switching means and said plurality of lamp intensity control means, for inverting said first plurality of low power electrical signals.

9. Apparatus having a pair of output terminals, for controlling the intensity of a lamp comprising:

a. integrating summation means for generating a first signal;

b. means for generating a second signal having a sawtooth waveform;

c. means for supplying a d-c signal to said integrating means;

d. electronic switch means for supplying a third signal to said integrating means,.said electronic switch means being gated by the output signal ofthe nextmentioned comparator means, to produce said third signal;

e. comparator means responsive to said first and second signals for generating an output signal, said output signal having a first voltage level when the magnitude of the first input signal exceeds the magnitude of the second, and having a second voltage level when the magnitude of the second input signal exceeds the magnitude of the first;

f. means for coupling the output of said comparator means to said electronic switch means;

g. means for generating a negative fullwave rectified sine wave; and coupling said sine wave generating means to the input of said electronic switch means;

h. means for supplying time-varying voltage to said pair of output terminals;

i. means for controlling the waveform of said timevarying voltage comprising controlled rectifier means;

j. means for generating and coupling a firing signal to said controlled rectifier means; and

k. means for coupling the output of said comparator means to the input of said firing signal generating means, comprising an optical coupled switch 

1. An apparatus for creating lighting effects comprising: a. means for generating a first plurality of low power electrical signals, includlng at least: i. means for supplying audio signals; and first means responsive to said audio signals and having at least three output terminals, for generating first, second, and third low power electrical d-c signals at each of said terminals, respectively, in a predetermined sequence, and at a predetermined rate, said rate being controlled by the amplitude of said audio signals; and ii. means for generating at least one low power electrical signal having a triangular waveform; b. means for electrically coupling said low power electrical signals to said next-mentioned programable swItching means; c. programable switching means comprising in combination: i. a plurality of input terminals corresponding on a one to one basis with said plurality of low power electrical signals electrically coupled from said generating means; ii. a plurality of output terminals corresponding on a one to one basis with the below-mentioned plurality of lamp intensity control means; and iii. means for electrically intercoupling said input terminals and said output terminals in a predetermined order; d. a second plurality of lamp intensity control means, each having input terminal means, responsive solely to said low power electrical signals intercoupled to said output terminals; and e. means for electrically coupling said output terminals to said input terminal means of said plurality of lamp intensity control means.
 2. An apparatus according to claim 1 in which said generating means further includes second means also responsive to said supplied audio signals for converting said signals into at least one d-c low power electrical signal, having an amplitude proportional to the amplitude of said supplied audio signals.
 3. Apparatus according to claim 2, wherein each of said second plurality of lamp intensity control means has a pair of output terminals for connection to a lamp, and comprises: a. integrating summation means for generating a first signal; b. means for generating a second signal having a sawtooth waveform; c. means for supplying a d-c signal to said integrating means; d. electronic switch means for supplying a third signal to said integrating means, said electronic switch means being gated by the output signal of the next-mentioned comparator means, to produce said third signal; e. comparator means responsive to said first and second signals for generating an output signal, said output signal having a first voltage level when the magnitude of the first input signal exceeds the magnitude of the second, and having a second voltage level when the magnitude of the second input signal exceeds the magnitude of the first; f. means for coupling the output of said comparator means to said electronic switch means; g. means for generating a negative fullwave rectified sine wave; and coupling said sine wave generating means to the input of said electronic switch means; h. means for supplying time-varying voltage to said pair of output terminals; i. means for controlling the waveform of said time-varying voltage comprising controlled rectifier means; j. means for generating and coupling a firing signal to said controlled rectifier means; and k. means for coupling the output of said comparator means to the input of said firing signal generating means, comprising an optical coupled switch means.
 4. Apparatus according to claim 2 wherein first means responsive to said audio signals comprises: a. means for generating a first signal having a sawtooth waveform; b. means for supplying a second signal having a fixed voltage; c. means for supplying a third signal having a fixed voltage; d. first comparator means responsive to said first and second signals for generating a first output signal, having a first d-c voltage level when the instantaneous amplitude of the first signal exceeds the magnitude of the said second signal; e. second comparator means responsive to said first and third signals for generating a second output signal, having a predetermined d-c voltage level when the magnitude of the third signal exceeds the instantaneous amplitude of the first signal; f. means responsive to the output signals of said first and second comparator means, said means including an outupt port and potentiometer means for varying the signal level at said output port for generating a third output signal having a first voltage level when there exists a d-c voltage level at either output of said first and second comparators, and for generating an output signal having a second vOltage level, when a d-c voltage is absent from both outputs of said first and second comparator means; g. means for controlling the period of said first signal having a sawtooth waveform, in response to the amplitude of the said audio signals; and h. potentiometer means for varying the maximum level of the output signals of said first and second comparator means.
 5. Apparatus according to claim 3 wherein first means responsive to said audio signals comprises: a. means for generating a first signal having a sawtooth waveform; b. a means for supplying a second signal having a fixed voltage; c. a means for supplying a third signal having a fixed voltage; d. first comparator means responsive to said first and second signals for generating a first output signal, having a first d-c voltage level when the instantaneous amplitude of the first signal exceeds the magnitude of the said second signal; e. second comparator means responsive to said first and third signals for generating a second output signal, having a predetermined d-c voltage level when the magnitude of the third signal exceeds the instantaneous amplitude of the first signal; f. means responsive to the output signals of said first and second comparator means, said means including an output port and potentiometer means for varying the signal level at said output port for generating a third output signal having a first voltage level when there exists a d-c voltage level at either output of said first and second comparators, and for generating an outupt signal having a second voltage level, when a d-c voltage is absent from both outputs of said first and second comparator means; g. variable resistance means for controlling the period of said first signal having a sawtooth waveform, in response to the amplitude of the said audio signals; and h. potentiometer means for varying the maximum level of the output signals of said first and second comparator means.
 6. An apparatus for creating lighting effects comprising: a. means for generating a first plurality of electrical signals; b. a second plurality of lamp intensity control means wherein each of said second plurality of control means has a pair of output terminals for connection to a lamp, and comprises: i. integrating summation means for generating a first signal; ii. means for generating a second signal having a sawtooth waveform; iii. means for supplying a d-c signal to said integrating means; iv. electronic switch means for supplying a third signal to said integrating means, said electronic switch means being gated by the output signal of the next-mentioned comparator means, to produce said third signal; v. comparator means responsive to said first and second signals for generating an output signal, said output signal having a first voltage level when the magnitude of the first input signal exceeds the magnitude of the second, and having a second voltage level when the magnitude of the second input signal exceeds the magnitude of the first; vi. means for coupling the output of said comparator means to said electronic switch means; vii. means for generating a negative fullwave rectified sine wave; and coupling said sine wave generating means to the input of said electronic switch means; viii. means for supplying time-varying voltage to said pair of output terminals; ix. means for controlling the waveform of said time-varying voltage comprising controlled rectifier means; x. means for generating and coupling a firing signal to said controlled rectifier means; and xi. means for coupling the output of said comparator means to the input of said firing signal generating means, comprising an optical coupled switch means; and c. means for selectively switching said plurality of electrical signals to said plurality of intensity control means.
 7. An apparatus according to claim 4 wherein the means for controlling the period of said first signal compriSes a variable resistance means.
 8. An apparatus according to claim 2, further including means, electrically connected between said output terminals of said programable switching means and said plurality of lamp intensity control means, for inverting said first plurality of low power electrical signals.
 9. Apparatus having a pair of output terminals, for controlling the intensity of a lamp comprising: a. integrating summation means for generating a first signal; b. means for generating a second signal having a sawtooth waveform; c. means for supplying a d-c signal to said integrating means; d. electronic switch means for supplying a third signal to said integrating means, said electronic switch means being gated by the output signal of the next-mentioned comparator means, to produce said third signal; e. comparator means responsive to said first and second signals for generating an output signal, said output signal having a first voltage level when the magnitude of the first input signal exceeds the magnitude of the second, and having a second voltage level when the magnitude of the second input signal exceeds the magnitude of the first; f. means for coupling the output of said comparator means to said electronic switch means; g. means for generating a negative fullwave rectified sine wave; and coupling said sine wave generating means to the input of said electronic switch means; h. means for supplying time-varying voltage to said pair of output terminals; i. means for controlling the waveform of said time-varying voltage comprising controlled rectifier means; j. means for generating and coupling a firing signal to said controlled rectifier means; and k. means for coupling the output of said comparator means to the input of said firing signal generating means, comprising an optical coupled switch means. 